I have a a BCM lower that is an SBR and I mainly use it for .223
I am building a 9mm upper for it and I was wondering if the H3 buffer that I have will work or do I have to switch it to a 9mm buffer.
I read several articles on google about the difference, and the only thing I could find was a .2 oz weight difference.
Some said the length is difference and others say no they are the same. I dont have a 9mm buffer to compare the two so I dont know.
So do I need to get a 9mm buffer and switch them back and forth when I change uppers?
I have thousands of trouble free rounds through my 2 9mm uppers with an H3. The difference is the H3 is a 5.4oz inertial buffer (with the balls rolling inside) and the 9mm is a 5.5oz solid buffer.
9mm is tough, and I don’t have any experience fooling around with them. For 9mm, heavier is better. Maybe consider a Vltor A5 with the A5 H3 or H4 buffer?
9mm buffers allow bolt bounce even in semi-auto fire…which is never a good thing. BB is just not as critical when firing 9mm vice firing rifle cartridges.
Many of these 9mm buffers will run you $50-$75. A Vltor A5 setup runs about $100…and it shoots oh-so-smooth for the 5.56. Still, all I got is a WAG.
Hopefully somebody with more real-world experience will chime in.
Do you also need to run a buffer spacer? I see spike’s pushing to use one, but no other company really says to use one. So should you use one with the 9mm buffer, or is it just a waste of money?
From what I have gathered form the interwebz, those buffer spacers are used to prevent the BCG from over-running the bolt catch by too great a margin. Apparently, using some of these heavier 9mm buffers, people are breaking bolt catches when there is too much space between the bolt at full retraction and the bolt catch.
I think that’s why some 9mm buffers have a longer OAL than std carbine buffers.
I highly recommend using a heavy buffer like the
Spikes or Slash 9Q. They are heavy enough to really smooth out the 9mm action and long enough to prevent breaking your bolt catches. Money well spent in my opinion.
IF we’re talking about the various engineered buffers, super heavy, and long/ SlashQ type, the main reason for the length is to take the stress off the hammer pin and, depending on what block you’re running, the bolt catch. The extra weight reduces bolt velocity.
Run an H3. Install KNS extended SS pins. You won’t have a problem… even suppressed.
